- You two should have killed me back there.
- Why? You don't have a particularly good head.
- You wouldn't look at all well over a mantel.

10 seconds sound clip from the X Minus 1 - A Gun for Dinosaur by L. Sprague de Camp classic radio drama series.

You can hear this line at 00:22:44 in the radio play.

Quote context

[...]

- Nice work, Raja old chap!

- Yes. Cretaceous rock. Doesn't quite have the balance of a cricket ball, but... it's a bit harder, what?

- Well, suppose we tie this chap up and take him back to camp.

- When the time transition chamber finally arrived, we fell over one another getting into it.

- We dumped James in a corner, and threw the switches.

- You two should have killed me back there.

- Why? You don't have a particularly good head.

- You wouldn't look at all well over a mantel.

- You can laugh... but I'll get you some day. Close quarters, isn't it? Some day, I'll find a way. I'll find a way and I'll get off scot-free, too.

- My dear chap! If there were some way to do it, I'd have you charged with Holtzinger's murder.

- Look, you'd best let well enough alone.

- No. No. I'll kill you. Both of ya. Somehow.

[...]